This Keto Chicken Spaghetti Bake is a creamy, cheesy, low-carb comfort food made with tender chicken breast, zucchini noodles, cream cheese, heavy cream, tomatoes, and melted mozzarella. It delivers all the cozy flavors of a traditional chicken spaghetti casserole without the high-carb pasta.
Prep time
15 minutes
Cook time
25–30 minutes
Servings
4–6
Ingredients
For the chicken and zucchini
- 1 lb (450 g) boneless, skinless chicken breast, diced
- 3 medium zucchini, spiralized into noodles
- 1 cup diced tomatoes, preferably no added sugar
- 1 tsp Italian seasoning
- ½ tsp garlic powder
- Salt and black pepper, to taste
- 1 tbsp olive oil
For the creamy cheese sauce
- 4 oz (115 g) cream cheese, softened
- ½ cup (120 ml) heavy cream
- 1½ cups shredded mozzarella cheese, divided
- ⅓ cup grated Parmesan cheese
- ½ tsp onion powder, optional
- 1–2 tbsp chicken broth, if needed to thin the sauce
Instructions
Step 1: Prepare the oven
Preheat your oven to 375°F (190°C). Lightly grease a medium baking dish with olive oil or cooking spray.
Prepare the zucchini noodles using a spiralizer. If the zucchini is particularly watery, place the noodles in a colander, sprinkle lightly with salt, and let them sit for 10 minutes. Pat dry with paper towels.
Step 2: Season and cook the chicken
Cut the chicken breast into bite-sized pieces.
Season with Italian seasoning, garlic powder, salt, and black pepper.
Heat the olive oil in a large skillet over medium-high heat. Add the chicken in a single layer and cook for approximately 5–7 minutes, stirring occasionally, until lightly golden and cooked through. The internal temperature should reach 165°F (74°C).
Transfer the chicken to a plate and set aside.
Step 3: Make the creamy cheese sauce
Reduce the skillet heat to medium-low. Add the softened cream cheese and heavy cream.
Stir continuously until the cream cheese melts and the mixture becomes smooth and creamy.
Add the optional onion powder. If the sauce is too thick, stir in 1–2 tablespoons of chicken broth until it reaches a pourable consistency.
Avoid boiling the sauce vigorously, as this can cause it to separate.
Step 4: Add the zucchini noodles
Add the spiralized zucchini noodles to the skillet and gently toss them in the sauce.
Cook for just 1–2 minutes, stirring gently. The zucchini should soften slightly but remain firm because it will continue cooking in the oven.
If excess liquid collects in the skillet, drain it carefully before proceeding. This step helps prevent a watery casserole.
Step 5: Combine the ingredients
Return the cooked chicken to the skillet.
Add the diced tomatoes and ¾ cup of shredded mozzarella. Stir until the chicken, zucchini noodles, tomatoes, and cheese are evenly coated in the creamy sauce.
Taste and adjust the salt, pepper, or Italian seasoning as needed.
Step 6: Assemble the casserole
Transfer the mixture into the prepared baking dish, spreading it evenly.
Sprinkle the remaining ¾ cup mozzarella over the top, followed by the grated Parmesan cheese.
For extra flavor, add a light sprinkle of Italian seasoning.
Step 7: Bake until golden and bubbly
Place the baking dish in the preheated oven and bake uncovered for 20–25 minutes, until the cheese is melted, bubbling, and lightly golden.
For a more golden cheese topping, switch on the broiler for the final 1–2 minutes, watching carefully to prevent burning.
Step 8: Rest and serve
Remove the casserole from the oven and let it rest for 5–10 minutes. This allows the sauce to settle and makes serving easier.
Garnish with chopped parsley or fresh basil, if desired.
Serve warm as a satisfying low-carb lunch or dinner.
Tips for the best keto chicken spaghetti bake
- Prevent watery zucchini: Salt, drain, and pat the zucchini noodles dry before cooking.
- Use softened cream cheese: It blends more easily into a smooth sauce.
- Choose tomatoes carefully: Use plain diced tomatoes without added sugar and check the label for carbohydrate content.
- Shred your own mozzarella: It often melts more smoothly than pre-shredded cheese.
- Increase the protein: Add a little extra chicken breast or use a higher-protein cheese.
- Make ahead: Cook the chicken and prepare the sauce in advance. Add the zucchini closer to baking time for a firmer texture.
Approximate nutrition
Per serving, assuming 6 servings and depending on the ingredients used:
| Nutrient | Approximate amount |
|---|---|
| Calories | 300–360 kcal |
| Protein | 28–33 g |
| Fat | 18–24 g |
| Total carbohydrates | 5–8 g |
| Fiber | 1–2 g |
| Net carbohydrates | 4–6 g |
